I have lots of unit test code with lines like this:

@Test def bar() {
    ...
    val Seq(_, _) = foo() // produces warning unused
    ...
}

When I have warn-unused turned on, I get a warning on this:

private val in method bar is never used.

But notice, there is no val here. I've used the underscore here.

I don't have a workaround to suppress this warning other than rewriting as

@Test def bar () {
    foo() match { case Seq(_,_) => /* ok */ }
}

Having to permute the source code into a match-case just to suppress this spurious warning is painful, and there is a loss of code symmetry I don't like, as lots of other very similar tests look like:

@Test def bar2() {
    val Seq(a, _) = foo2()
    assertEquals("a", a)
}

This does not produce the spurious warning.